Fungal pre-treatment of forestry biomass with a focus on biorefining: A comparison of biomass degradation and enzyme activities by wood rot fungi across three tree species

Abstract

The fungal enzyme activities and breakdown of wood components may be influenced by the fibrous and structural composition across different wood species. White-rot fungi were inoculated onto wood chips of F. excelsior, A. pseudoplatanus or Q. robur and incubated for 28 days revealing that most fungi appeared to successfully colonize the different types of wood chips. Fibre analysis revealed that the fungi causing the highest mass losses in F. excelsior and A. pseudoplatanus were those that degraded more cellulose compared with hemicellulose or lignin. Fungal degradation leading to high mass losses of Q. robur was more complicated as lignin-degrading activities became more important. The structural composition in terms of the largest vessel sizes only showed an inverse correlation with remaining moisture content and not with mass loss or fibre degradation. These results provide an insight into fungal degradation of wood from three common tree species, and the link between the compositional characteristics of each wood type and the ease of degradation. This could have an impact on future biological pre-treatment strategies and valorisation approaches for forestry residues in integrated biorefineries.